The immune system is composed of many interdependent cell types that collectively protect the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have specialized functions.
For example, dendritic cells play a pivotal role in inducing a primary immune response by capturing and presenting antigens to the cells of the adaptive immune system (e.g., B cells) that are responsible for the production of antibodies. In addition, both of these cell types secrete important classes of small molecular weight immunostimulatory proteins such as cytokines and chemokines.
Dendritic cell and B cell activity is compromised or insufficient in a wide range of human diseases. Thus, there is an ongoing need for compositions that increase the populations of these cells or enhance their activity in immunity.
Ganoderma species (a group of medicinal fungus) is known in the art. Ganoderma lucidum (Reishi or Ling-Zhi) has been used as traditional Chinese medicine (TCM) for promoting good health, perpetual youth, and longevity (Shiao, M. S., K. R. Lee, L. J. Lin, and C. T. Wang. in Food Phytochemicals for Cancer Prevention II: Teas, Spices, and Herbs. C. T. Ho, T. Osawa, M. T. Huang, and R. T. Rosen, eds. American Chemical Society, Washington D.C., 1994, p. 342-354). Extracts of Reishi have been used as anti-tumor and immuno-modulating agents. (Sone, Y., R. Okuda, N. Wada, E. Kishida, and A. Misaki, in Agric. Biol. Chem. 1985 49:2641-2653; Wang S.-Y., Hsu M.-L. and Hsu H., Int. J. Cancer 1997 70, pp. 699-705; Vetvicka V., Thornton B. P. and Ross G. D., J. Clin. Invest. 1996 98, pp. 50-61; Van Strijp J. A. G., Russel D. G., Tuomanen E., Brown E. J. and Wright S. D., J. Immunol. 1993 151, pp. 3324-3336; Muller A., Rice P. J., Ensley H. E., Coogan P. S., Kalbfleisch J. H., Kelley J. L., Love E. J., Portera C. A., Ha T., Browder I. W. and Williams D. L., J. Immunol. 1996 156, pp. 3418-3425; Lee, S. S., Y. H. Wei, C. F. Chen, S. Y. Wang, and K. Y. Chen. Int. J. Chin. Med. 1995 6:1-12.) A fucose-containing glycoprotein fraction of Ganoderma lucidum Reishi extract has been found to be useful for stimulating the expression of an inflammatory cytokine or modulating differentiation of a mononuclear cell by Wong et al., WO 2006/44616, published Apr. 27, 2006, the disclosure of which is incorporated herein by reference in its entirety.